existing underground utilities are identified, use ex-treme care when working near them. Ripping up utilitylines adds loss time to a project, adds to the cost of theproject, and causes an inconvenience to people to whomthe utilities were supporting.NOTE: Obtain a digging permit before perform-ing any excavations on a project.Symbols for electric power distribution are shownin figure 15-10. Note the location of these lines notonly for the reasons stated about pipe but also becauseof the risk of electric shock when a machine cuts anelectric line.NOTE: On some occasions certain items aremistakenly left out on new drawings. Examples areburied telephone cables, electrical lines, waterlines,and fuel lines. Because of this, you must make it apractice to compare older drawings with new drawingsand to your freehand sketches.Symbols for building material are shown in figure15-11. These symbols are used in cross sections orcutaway views. They also label material as new orexisting.SketchesA freehand sketch is a drawing, made without theuse of mechanical aids or devices. Sketches may bedrawn on graph paper, traced, or drawn with a--straightedge. A sketch may be of an object, an idea, ora combination of both. The ability to make quick,accurate sketches is helpful in conveying your ideasto others.Two examples of freehand sketches are shown infigures 15-12 and 15-13. These sketches wereFigure 15-11.—Material symbols.Figure 15-10.—Electrical power distribution symbols.15-8
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business